In recent years, gasoline powered string trimmers and gasoline powered blowers have experienced greater use by commercial gardeners and by owners of residences. Such gasoline powered string trimmers and gasoline powered blowers are typically operated where the throttle portion of the carburetor is in a wide open position. However, when a gasoline powered string trimmer is used along a chain link fence or along a concrete wall, it is often desirable to reduce the speed of the engine to avoid rapid consumption of the cutting line caused by contact of the cutting line with the chain link fence or the concrete wall. When using gasoline powered blowers, it is also desirable to reduce the engine speed of these blowers when attempting to gather together a small pile of debris for easy pickup or when blowing debris out of confined areas. Reducing the engine speed of a string trimmer or a blower requires repositioning the trigger.
Prior art throttle control systems found on string trimmers and blowers are designed to use the first and second fingers of an operator's right hand to move the trigger. Accordingly, the position of the first and second fingers of an operator's right determine the position of the trigger which in turn, determines the speed of the gasoline powered engine. At full speed all the fingers on the operator's right hand are together and can comfortably support the weight of the string trimmer or blower. At reduced speeds partial movement of the trigger to achieve a reduced speed of the gasoline engine causes the full weight of either the string trimmer or the blower to be supported by only the ring and little fingers of the right hand instead of all four fingers. Prolonged two finger support of a string trimmer or a blower is particularly uncomfortable for the operator and could possibly create a dangerous operational condition.
There is therefore a need in the art to provide a throttle control system for a gasoline powered string trimmer or blower which allows the operator to comfortably support the weight of a gasoline powered string trimmer or blower in the same manner that it is supported when the engine is in full operating speed yet, at the same time, permit the engine to run at a reduced engine speed.